The myth of the eight-hour sleep

BBC News - The myth of the eight-hour sleep:

'via Blog this'

We often worry about people who lie awake in the middle of the night - but it could be good for you. Scientists have been saying for 20 years that the eight-hour sleep may be unnatural, and historians increasingly are backing them up.

In the early 1990s, psychiatrist Thomas Wehr conducted an experiment in which a group of people were plunged into darkness for 14 hours every day for a month.

It took some time for their sleep to regulate but by the fourth week the subjects settled into a very distinct sleeping pattern. They slept first for four hours, then woke for one or two hours before falling into a second four-hour sleep.